[libvirt-users] Snapshot overlay-file deletion

[Gionatan Danti]

Hi list,
issuing the command "virsh blockcommit --delete --pivot" (on a
previously created external snapshot/overlay) returns an error regarding
an unsupported flag warning stating "error: unsupported flags (0x2)". I
need to manually "rm" the affected file after the blockcommit.

A similar issue was reported many years ago here [1]. Am I missing
something, or is the "--delete" flag not supported?
Thanks.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1001475

[Eric Blake]

Post by Gionatan Danti
Hi list,
issuing the command "virsh blockcommit --delete --pivot" (on a
previously created external snapshot/overlay) returns an error regarding
an unsupported flag warning stating "error: unsupported flags (0x2)". I
need to manually "rm" the affected file after the blockcommit.
A similar issue was reported many years ago here [1]. Am I missing
something, or is the "--delete" flag not supported?

The qemu driver still does not implement the flag. Yes, it's a known
issue for many years now, but it is surprisingly complex to come up with
semantics for deletion of an external snapshot in a way that doesn't
corrupt data, so no one has tackled that code project.

[Gionatan Danti]

Post by Eric Blake
The qemu driver still does not implement the flag. Yes, it's a known
issue for many years now, but it is surprisingly complex to come up
with semantics for deletion of an external snapshot in a way that
doesn't corrupt data, so no one has tackled that code project.

Mmm... if I am expected to manually delete the inactive overlay file
(after a successful blockcommit --pivot), why can not libvirt/qemu do
the same? I mean, a simple rm of the inactive (just commited) file...

Thanks.